The Penates were deities
selected by each family, and frequently by its individual members, as a special
protector. Various causes led to this selection. If, for instance, a child were
born on the festival of Vesta, it was thought that that deity would
henceforward act as its special guardian. If a youth possessed great business
talents he adopted Mercury as his tutelary deity; should he, on the other hand,
develop a passion for music, Apollo was selected as his patron god, and so
forth. These became regarded as the special divinities of the household, small
images of them adorned the surroundings of the hearth, and honours similar to
those paid to the Lares were accorded to them.

Just as there were public Lares
so there were public Penates, which were worshipped by the Roman people under
the form of two youthful warriors, who, in later times, were regarded as
identical with Castor and Pollux. They are generally represented on horseback,
with conical caps on their heads, and bearing long spears in their hands.